Life After Death
Trees are all-around awesome. And guess what? They're almost as valuable after death as in life. Consider this: there can be more living biomass in a dead standing tree than a same-sized living tree. Would that we all could leave behind such a legacy.
A log is of course a tree, or part of one, that’s fallen to the ground. A term I didn’t know until recently is “snag,” which is a dead tree that’s still standing. Snags and logs may look like waste material to you and me, but to a whole world of wildlife they’re high-end real estate.
When a tree dies, some of the first responders are wood-boring insects. Their tunnels attract other insects and organisms, such as fungi. Then come the woodpeckers who eat those insects and organisms. In their search for snacks, the woodpeckers open up bigger holes. These cavities support songbirds and small mammals and reptiles. Weather and small-critter activities eventually enlarge the holes further, attracting owls and other mid-size critters. For all of these animals, dead trees provide safe places for sleeping, raising young, foraging, storing food, hiding from predators and surviving cold and wet weather. Snags also make great lookout towers for raptors.
Woodpeckers are known as primary cavity excavators, since they can chisel holes into wood that appears intact. While they’re capable of chipping away at living wood, they prefer decaying wood because it’s a) softer and b) stocked with invertebrate munchables. Downy, hairy, red-bellied, red-headed, and pileated woodpeckers, as well as northern flickers, all rely on dead trees or limbs.
Birds that move into pre-fab holes are known as secondary cavity nesters. Some will expand their new digs, or cozy them up with twigs, leaves, weeds, bark, feathers, snakeskin and animal fur. Some 80 species of birds rely on dead trees as habitat. A partial list of these secondary cavity nesters includes eastern screech owls, American kestrels, tree swallows, eastern bluebirds, tufted titmice, purple martins, Carolina and house wrens, Carolina chickadees and white-breasted nuthatches.
Snags and logs will eventually rot into the ground. But until then, they’ve enjoyed an illustrious second career hosting countless other living creatures.
If you’re hoping to welcome wildlife back to your yard, you’ll definitely want to include native trees of the living variety. How about also embracing some logs or snags?
As much as safety and aesthetics permit, allow trees to live out their life cycles undisturbed.
If you’re felling a problematic or dying tree, consider leaving a snag standing or keeping logs on your property. We had to take down a few trees earlier this year, so we stashed multiple logs along a fence line and left one snag standing.
Drilling holes into fresh snags will hasten the decomposition process by making them more accessible to a range of organisms.
You can hide snags and logs away in inconspicuous spots or – better yet – repurpose them as sculpture. Some botanical gardens are making artistic use of these opportunities.
Consider creating a brush pile with fallen branches and decommissioned Christmas trees. Done right, these can be both practical and attractive.
As humans, we may or may not believe a life after death awaits us. But we can all leave a legacy. If a healthier and more beautiful planet is part of the bequest we’d like to pass on, let’s make sure the trees in our care get to complete their full cycles of both life and death.
Resources
Heather Evans, “1000+ Reasons to Love a Snag,” Dear Avant-Gardener, August 20, 2022. (This is a great newsletter, by the way. I recommend subscribing!)
Josie Miller, “Tree Cavities Are for the Birds,” University of Kentucky Urban Forest Initiative.
Stuart Niven, “Tim-ber? … Not So Fast: The Important Role of Dead and Dying Trees,” Seattle Audubon Society, March 7, 2022.
George Wuerthner, “The Ecological Value of Dead Trees,” The Wildlife News, December 20, 2018.
“Dead Trees Can Support a Lot of Life,” California Audubon.
“Did You Know? Dead Trees Play an Important Role,” Monthly Newsletter, Forest Preserves of Cook County, July 2, 2015.
“Trees and Snags,” National Wildlife Federation.
Thanks for that context, J.E.
Perfect. That's what they are!